In a sham-controlled, double-blind, cross-over study four chronic schizophrenic subjects received weekly hemodialysis or sham dialysis treatments, including at least 16 consecutive hemodialysis treatments. No subjects improved during sham dialysis; however, three subjects showed improvement that may be related to receiving real hemodialysis, or to a synergistic effect from hemodialysis plus neuroleptic medication. No subjects fully remited during the trial; but, one subject had substantial improvement and two others had some improvement in psychotic symptoms and social adjustment. Twenty additional subjects will be studied.